Apparatus for delivering ocular implants into an anterior chamber of the eye

Abstract

An ocular implant adapted to be disposed within Schlemm's canal of a human eye with a body extending along a curved longitudinal central axis in a curvature plane, a first strut on one side of the implant and a second strut on an opposite side of the implant, the circumferential extent of the first strut with respect to the plane of curvature being greater than the circumferential extent of the second strut with respect to the plane of curvature. The invention also includes methods of using the implant.

What is claimed is: 
     
       1. A cannula for delivering an ocular implant into Schlemm's canal of an eye, comprising:
 a curved tube comprising a lumen configured to direct the ocular implant to a location within Schlemm's canal; 
 a trough portion disposed distally of the curved tube; and 
 a distal portion disposed distally of the trough portion, wherein the distal portion is asymmetric with respect to a medial plane of the curved tube, wherein the distal portion comprises a distal tip formed by an intersection of an upper camming surface and a lower camming surface, and wherein the distal tip is blunt. 
 
     
     
       2. The cannula of  claim 1 , wherein the distal portion is asymmetric with respect to the medial plane of the curved tube due to the upper camming surface being shorter than the lower camming surface. 
     
     
       3. The cannula of  claim 1 , wherein the lower camming surface is configured to guide the cannula over a scleral spur of the eye. 
     
     
       4. The cannula of  claim 1 , wherein the distal portion is defined by an asymmetric V-shape. 
     
     
       5. The cannula of  claim 1 , wherein the trough portion is symmetric with respect to the medial plane. 
     
     
       6. The cannula of  claim 1 , where the cannula is shaped and dimensioned so that at least part some of the trough portion is advanced into Schlemm's canal while a first portion of the curved tube is disposed inside an anterior chamber of the eye and a second portion of the curved tube is extended through an incision in the eye to a location outside of the eye. 
     
     
       7. An  ophthalmic  system, comprising:
 a cannula comprising:
 a curved tube comprising a lumen, 
 a trough portion disposed distally of the curved tube, and 
 a distal portion disposed distally of the trough portion, wherein the distal portion is asymmetric with respect to a medial plane of the curved tube, wherein the distal portion comprises a distal tip formed by an intersection of an upper camming surface and a lower camming surface, and wherein the distal tip is blunt; and 
 
 an ocular implant configured to be advanced distally through the lumen and along the trough portion into Schlemm's canal of an eye. 
 
     
     
       8. The system of  claim 7 , wherein the distal portion is asymmetric with respect to the medial plane of the curved tube due to the upper camming surface being shorter than the lower camming surface. 
     
     
       9. The system of  claim 7 , wherein the lower camming surface is configured to guide the cannula over a scleral spur of the eye. 
     
     
       10. The system of  claim 7 , wherein the distal portion is defined by an asymmetric V-shape. 
     
     
       11. A method for inserting an ocular implant into Schlemm's canal of an eye, comprising:
 advancing a cannula through an anterior chamber of the eye, wherein the cannula comprises a curved tube, a trough portion disposed distally of the curved tube, and a distal portion disposed distally of the trough portion, wherein the distal portion is asymmetric with respect to a medial plane of the curved tube, wherein the distal portion comprises a distal segment and a proximal segment positioned proximally of the distal segment, wherein the distal segment has a cross-sectional curvature that is less curved than the cross-sectional curvature of the proximal segment of the distal portion; 
 inserting the distal portion into Schlemm's canal such that at least part of the trough portion is in fluid communication with Schlemm's canal; and 
 advancing the ocular implant through a lumen of the curved tube and along the trough portion into Schlemm's canal. 
 
     
     
       12. The method of  claim 11 , further comprising allowing a lower camming surface of the distal portion to contact a scleral spur of the eye to guide the distal portion and at least part of the trough portion into Schlemm's canal. 
     
     
       13. The method of  claim 12 , further comprising allowing an upper camming surface of the distal portion to contact scleral tissue of the eye to guide the distal portion and at least part of the trough portion into Schlemm's canal. 
     
     
       14. The method of  claim 13 , wherein the distal portion is asymmetric with respect to the medial plane of the curved tube due to the upper camming surface being shorter than the lower camming surface.